Saw blade guide and components therefor

ABSTRACT

An air jet containing blade guide for stabilizing a band saw blade or a circular saw blade of a saw mill and guide blocks or inserts for a saw blade guide are disclosed. The inserts can be removably fastened to a blade guide by means of cap screws preferably containing a hex socket for tightening and loosening the screws with a hex wrench. Cap screw holes formed in the inserts contain recessed countersinks for recessing the heads of the cap screws below a blade opposing surface of the inserts when disposed in an operative position of a blade guide in a saw mill. The inserts can be constructed of brass or aluminum bronze which is softer than the blade being stabilized thereby to avoid undue blade damage but which are hard enough to provide good wearability and heat dissipation as against periodic blade impacts. The blade guide disclosed contains a threaded air inlet port and an air passageway extended between the port and a side of the guide facing a work piece when the guide is operatively positioned in the mill to permit high pressure air supplied to the input port to be directed toward the kerf of the work piece to clean the latter of saw dust.

BACKGROUND OF THE INVENTION

[0001] This invention relates generally to blade guides and blocks orinserts used on such guides to stabilize a circular saw blade or bandsaw blade of a saw mill. More specifically, this invention relates to anair jet containing blade guide for use in cleaning the kerf of a workpiece and to inserts for saw blade guides.

[0002] Broadly speaking, blade guides have long been known and used forstabilizing both band saw and circular saw blades in saw mills. Whilesome early saw blade guides, such as those disclosed in U.S. Pat. No.425,105 to R. McChesney issued on Apr. 8, 1890, use inserts or blockswhich are removably fastened to the saw blade guide by means of threadedfasteners, none of these prior art inserts use cap screws for holdingthe inserts in place which are countersunk within the insert which arethreadably inserted onto and removed from a blade opposing surface ofthe insert and guide surface upon which the insert is mounted. Moreover,none of the prior art inserts which are mounted on the blade guides areconstructed of aluminum brass or aluminum bronze. Further, none of theprior art guides upon which inserts are mounted contain air passagewayswhich open toward the kerf of the work piece being formed in the mill inwhich the guide and insert is mounted therein.

[0003] By means of my invention, these and other difficultiesencountered using prior art guides and inserts are substantiallyeliminated.

SUMMARY OF THE INVENTION

[0004] It is an object of my invention to provide a novel metal insertfor a blade guide of a saw mill.

[0005] It is a further object of my invention to provide a novel metalinsert for a blade guide which is removably attachable to the guide.

[0006] It is a further object of my invention to provide a novel metalinsert for a blade guide which is constructed of aluminum bronze orbrass.

[0007] It is another object of my invention to provide a novel air jetcontaining blade guide for either a band or circular saw mill.

[0008] Briefly, in accordance with my invention there is provided ametal insert for a saw blade guide for stabilizing a saw blade. Theinsert comprises a block of material attachable to a saw blade guide.The material is selected from the group consisting essentially ofaluminum-copper alloys of bronze and of brass which have a BrinellHardness Number of between about 110 to 321.

[0009] Further, in accordance with my invention, there is provided ablade guide for mounting a blade stabilizing insert thereon. The guideincludes a base plate and a block disposed on the base plate andrecessed from a free end of the base plate. The block defines aninteriorly threaded blind hold forming an air inlet port which opensonto a surface of the block for attachment thereto of an exteriorlythreaded air outlet connector of a remote high pressure air source. Theblock also defines a hollow air passageway extending from the air inletport to an opening on a side of the block which faces a work piece whenthe guide is disposed in an operative position in a saw mill. Theopening is disposed at about the same level as that of a saw blade beingstabilized by the guide when the latter is operatively positioned.

[0010] These and other objects, features and advantages of the presentinvention will become apparent to those skilled in the art from thefollowing detailed description and attached drawings upon which, by wayof example, only the preferred embodiments of my invention areillustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 shows an exploded perspective view of a saw blade guideassembly, thus illustrating a preferred embodiment of my invention.

[0012] FIGS. 2-3 show a front elevation view and a top plan view,respectively, of a novel angle type blade guide containing a novel metalinsert, the guide and insert being components of the assembly of FIG. 1.

[0013]FIG. 4 shows a side elevation view of the angle guide of FIGS. 1-3together with inserts and fragments of a straight guide and of a bandsaw blade the same as shown in FIG. 1 except now being in operativepositions relative to one another.

[0014] FIGS. 5-6 show a side elevation view and a top plan view,respectively, of a novel saw blade guide which is an alternative to theangle guide of FIGS. 1-4, thus illustrating another important embodimentof my invention.

[0015]FIG. 7 shows a perspective view of the blade guide of FIGS. 5-5 asused in stabilizing a circular saw blade.

[0016] FIGS. 8-9 show a plan view and a longitudinal elevation view,respectively, of one of the novel metal inserts of FIGS. 1-4.

[0017] FIGS. 10-11 show a plan view and a longitudinal elevation view,respectively, of an alternative form of metal insert that can be used inplace of each of the inserts shown in FIGS. 1-4 and 8-9.

[0018]FIG. 12 shows a perspective view of another alternative form ofmetal insert that can be used in individually or in multiples in placeof each of the inserts as shown in FIGS. 1 and 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0019] Referring now to the drawing figures and, in particular, to FIGS.1 and 4 there is shown, in a preferred embodiment of my invention, animproved blade guide assembly, generally designated 10, for stabilizinga band saw blade 12 having cutting teeth 13 of a conventional band sawmill assembly, not shown, to limit or effectively prevent lateralvibration, bending or dishing of the blade during sawing operations. Atthe outset, it will be understood that the assembly 10 can also be usedto stabilize a circular saw blade of a circular saw mill such as isillustrated in FIG. 7 and as later more fully explained. The assembly 10includes a conventional straight guide 14, located adjacent one broadside of the blade 12 and an improved angle guide, generally designated16 (See also FIGS. 2-3) having a base plate 18 which is located adjacentthe other broad side of the blade. The guides 14 and 16 may be made ofany suitable high yield strength material such as, for example, AISIC1018 cold drawn steel or ASTM A-36 hot rolled steel. A novel pair ofblade guide blocks or inserts 20, 22 (See also FIGS. 2-3) is removablysecured to the blade opposing base plate 18 of the angle guide 16 and toa blade opposing surface 24 (See FIG. 1) of the straight guide 14 bymeans of threaded fasteners 26. The fasteners 26 are preferably flathead, socket head cap screws containing a hex socket 27 in the cap. Theguides 14 and 16 are conventionally attached, adjustably, to the sawmill assembly in the usual, well known manner, as, for example, by meansof bolts 28 located in elongated slots 30 and 32 of the guides, 14 and16, respectively. The slot 32 (FIGS. 1-3) is located in a back plate 34of the angle guide 16, the base plate 18 and back plate 34 of whichadjoin one another to form a generally L-shaped configuration and extendperpendicularly from one another.

[0020] The novel feature of the improved angle guide 16 as shown inFIGS. 1-4 comprises an elongated block member 36 which is formed in andalong the corner in which the plates 18 and 34 intersect and rises fromthe base plate along the back plate to a level which is above the levelof the blade 12 as it passes between the inserts 20 and 22 when theguide 16 is in its operative position in the saw mill, as best seen inFIG. 4. The block member 36 contains an interiorally threaded blind holeor socket forming an air inlet port 38 located near one side of theblock member, which port opens upwardly, as viewed, onto an uppersurface 40 thereof. The member 36 also contains a hollow passageway 42(See FIGS. 1-3) which extends parallel to and is spaced from the backedge of the blade 12 to an opening or air outlet port 44 located on aside 46 (FIGS. 2-4) of the guide 16 which faces a work piece, not shown,when the guide is in its operative position in the mill. When the guide16 is in its operative position, it is important that the opening 44 bedisposed very close to the same level as that of the blade 12 as seen inFIG. 4. The socket 38 can thus be fitted in an air tight manner with aconventional exteriorly threaded connector 45 of an air hose 47 (FIG. 1only) leading to an externally located high pressure air source suchthat high pressure air can be directed into the air inlet port 38,thence through the passageway 42 and out of the opening 44 close to anddirected alongside the back edge of the blade 12 and against a workpiece being operated on by the mill to blow saw dust from the kerfformed by the blade 12.

[0021] Preferably, the block 36 forms a second step in conjunction witha first step 48 (See FIGS. 1-4), the first step being recessedsufficiently from an outer edge of the base plate 18 to providesufficient space on which to mount the insert 22 on the base plate. Theraised first step 48 thus forms a backing wall for the insert 22 butallows the blade 12 to overlie an upper surface 50 thereof when theangle guide 16 is in its operative position in the mill. Preferably, theblock or step 36, step 48, base plate 18 and back plate 34 areintegrally formed as a single unitary angle blade guide component.

[0022] The blade guide assembly 10 of FIGS. 1 and 4 can also be used tostabilize a conventional circular saw blade as well as a band saw bladesuch as the blade 12. Moreover, the air inlet port 38 and passageway 42with opening 44 can also be used to clean the kerf of a work piece beingoperated on by such a circular saw blade. To use the assembly 10 with acircular saw, the angle guide 16 should be arranged so that the verticalside 46 of the guide 16, as viewed, faces a peripheral portion of theteeth of the circular saw blade as they enter the work piece. Assumingthe blade 12 of FIG. 4 is an outer peripheral wedge portion of acircular saw blade, the cutting teeth 13 of the blade would then be onthe left edge of the blade 12, as viewed, opposing but spaced from theblock 36, rather than being on the right edge as in the band saw of theexample previously discussed. Further, the blade guide assembly 10,including the straight guide 14 with its insert 20 and the opposingangle guide 16 with its insert 22, should be disposed in the circularsaw mill at an angle of from about 15 to 25 degrees from the work pieceas measured in a plane containing the saw blade such that, as thecircular saw rotates, a given tooth of the blade will rotate through theassembly 10 about 15 to 25 degrees of arc before it rotates into acutting position against the work piece.

[0023] Referring now to FIGS. 5-7, there is shown, in another importantembodiment of my invention, a saw blade guide assembly, generallydesignated 52, which, as in the case of the assembly 10 of the previousexample, can also be used to stabilize the blade of either a band or acircular saw. In the present example, the assembly 52 is shown in usewith a circular saw blade 54, a fragment of which is shown,schematically, in FIG. 5 with saw teeth assumed on and around an outerperipheral portion thereof. The assembly 52 includes an air jet sawblade guide, generally designated 56, and a straight guide 58 (FIG. 5only), which may be similar to the straight guide 14 of the previousexample. The guide 56 can also be used in place of the angle guide 16 ofFIGS. 1-4 and includes a base plate 60 containing a block 62 thereon.The block 62 is recessed sufficiently from an outer free edge of thebase plate 60 to permit an insert 64 to be removably mounted thereon. Asimilar insert 64 (FIG. 5 only) is removably attached to the straightguide 58. The block 62 extends above the base plate 60 to a level whichis above the blade 54 as best seen in FIG. 5 to permit placement throughthe block of a hollow air passageway 66 (See FIG. 6) between aninteriorly threaded blind hole, which functions as a high pressure airinlet port 68, and an opening 70 on a side of the block 62. The opening70 functions as an air outlet port so as to expel high pressure airtoward a work piece 72 (See FIG. 7) being operated upon by the saw blade54. The expelled air steam should be aligned so as to be directedtangent to the periphery of the blade teeth 74 entering the work piece.In this manner, the guide 56 operates to aid in stabilizing the blade 54and also to provide a high pressure air steam to clean the kerf in thework piece 72 formed by the blade. The block 62 should be formed so asto be sufficiently thick to permit the back of the guide 56 to besecurely attached to a conventional bolster 74 on the saw millcontaining the blade 54 as by means of suitable threaded members 76. Theinserts 64 may be of any suitable type but are preferably of the sametype as those shown at 20 and 22 of the previous example. As in theprevious example, the inserts 64 are preferably removably secured to thebase plate 60 by means of suitable flat head, socket head, cap screws78. As in the previous example, it is important that the surface of thehead 80 (See FIG. 5) of each of the screws 78 be disposed in acountersink in an upper surface portion of the inserts 64 so as to berecessed and spaced below the blade opposing surface of the insert.

[0024] Referring now also to FIGS. 8-9 the novel inserts 20, 22 of theassembly 10 of FIGS. 1-4 are shown in detail. These inserts 20, 22 arealso of the same type shown in the example of FIGS. 5-7 as at 64. Theyare constructed of copper aluminum alloy (bronze or brass). They musthave sufficient abrasion resistance, heat dissipation capability andwearability to be of practical use as inserts for band saw and circularsaw guides in that they will also have a reasonable service life.However, they must not be so hard that they will damage a rapidly movingblade being stabilized thereby when impacted by the blade, as will occurperiodically during normal use. When using a continuous cast aluminumbronze insert, I have found that such a material classified bySpecification ASTM B-505, Grades 952-959 will meet these requirements.Similarly, when using an individually cast aluminum bronze insert, Ihave found that such a material classified as ASTM B-148, Grades 952-959will also meet these requirements. The Brinell Hardness Number of suchaluminum bronze or brass inserts, as measured under a 3,000 kg load,should be within the range of about 110 to 321. For a BHN of less thanabout 110, I find that the insert lacks sufficient wearability forpractical use and for a BHN above about 321 the insert will ordinarilybe harder than the blade being stabilized wherein blade damage can beexpected upon impact with the insert. The insert of FIGS. 8-9, as alsoshown in the assembly 10 of FIGS. 1-4 and, of which are the same type asused in the assembly 52 of FIG. 5, have rounded edges 82 on oppositeends of blade opposing surface portions thereof, which ends extendtransversely relative to movement of the band saw blade 12 of FIGS. 1and 4). In the alternative, FIGS. 10-11 show the same type of aluminumbronze or brass insert 84 as those at 20, 22 of FIGS. 8-9 except thatthis insert contains a pair of beveled edges 86 on opposite ends of ablade opposing surface portion. Here, again, the beveled edges 86 extendtransversely with respect to the direction of band saw blade movement.In each of the inserts 82 and 84 of FIGS. 8-9 and 10-11, respectively,two untapped screw holes 88 are formed in a base portion thereof with arecessed frustroconical countersunk portion 90 formed above the screwhole 88, as viewed, so that a cap screw, such as is shown at 26 in FIGS.1 and 4, can be inserted therein to a level below an upper surface 91 ofthe insert. I recommend that the cap screws 26, as shown in the exampleof FIGS. 1-4 and as shown at 78 in the example of FIGS. 5-6, bepreferably of the hex socket type for use of a standard hex wrench tosecure and loosen the same from its corresponding guide, although othertypes of commonly known cap screws could be employed wherein a standardtool such as a screw driver could be used to secure and remove the samefrom its guide.

[0025] Referring now to FIG. 12, there is shown a blade guide insert,generally designated 92, which may be made of tungsten carbide, which isthe material from which conventional saw blade guide inserts arecommonly made. However, conventional tungsten carbide inserts arepermanently attached to blade guides by means of silver soldering,brazing or other fusion processes. In this example, I form a recessedcountersunk cap screw hole 94 through the insert 92 so that it may besecured in place on its saw blade guide by cap screws, preferably of thesame type as shown at 26 in FIGS. 1 and 4 and at 78 in FIGS. 5-6 and asexplained in the previous examples. Here, as in the previous examples,the cap screw hole 94 should be formed so that the countersink isrecessed below the level of the blade opposing surface 96 of the insert92 so that the head of the cap screw will not be impacted by the sawblade when the latter impacts the surface 96 of the relatively softertungsten carbide material.

[0026] Although the present invention has been illustrated and describedherein with respect to certain preferred embodiments, it is not intendedthat this patent should be limited in scope and coverage by such detailsother than as specifically set forth in the following claims.

I claim:
 1. A metal insert for a saw blade guide for stabilizing a sawblade, said insert comprising a block of material attachable to a sawblade guide, said material being selected from the group consistingessentially of aluminum-copper alloys of bronze and of brass which havea Brinell Hardness Number of between about 110 and
 321. 2. The metalinsert of claim 1 wherein said block is generally rectangularly shapedand includes rounded edges on opposite ends thereof which arepositionable on a band saw blade guide so as to extend transversely withrespect to movement of a band saw blade which is to be stabilizedthereby.
 3. The metal insert of claim 1 wherein said block is generallyrectangularly shaped and includes beveled edges on opposite ends thereofwhich are positionable on a band saw blade guide so as to extendtransversely with respect to movement of a band saw blade which is to bestabilized thereby.
 4. A metal insert for a saw blade guide forstabilizing a saw blade, said insert comprising a block of materialattachable to a saw blade guide, said material being selected from thegroup consisting essentially of tungsten carbide, brass and aluminumbronze, said block defining at least one countersunk fastener holetherein which is recessed from a blade opposing surface of said block,for attaching said block to a saw blade guide with at least one flathead cap screw fastener such that the head of said fastener ispositioned below the level of a saw blade opposing surface of said blockwhen said block is operatively secured to said saw blade guide.
 5. Themetal insert of claim 4 further comprising at least one flat head capscrew fastener for securing said block to said saw blade guide, said atleast one fastener including a head containing a hex socket forreceiving therein a hex head wrench for attaching and removing saidblock to and from said blade guide.
 6. The metal insert of claim 5wherein said at least one hole includes a cylindrically shaped portionwhich opens onto a blade opposing surface of said block, a cone shapedcountersunk portion which opens on maximum diameter thereof onto saidcylindrically shaped portion, and an untapped cylindrically shaped shaftportion which extends from a minimum diameter end of said countersunkportion to a base surface of said block.
 7. An improved angle guide fora saw blade guide assembly of a saw mill of the type whichconventionally includes a base plate for attachment of a saw bladestabilizing metal insert thereto and a backing plate adjoining one endof said base plate and extending at a right angle from said base platefor attachment to a saw mill assembly, the improvement of whichcomprises a block member disposed in a corner between said plates andextending along said corner parallel to and spaced from a back edge of aband saw blade of the mill when said angle guide is disposed in anoperative position, said block member defining an air inlet port openingonto a surface thereof for attachment to a source of high pressure air,said block member also defining a hollow passageway extending fromcommunication with said inlet port to an opening on a side of said blockmember for expelling high pressure air at the same level of the sawblade in the direction of a work piece to be cut by the saw blade forcleaning saw dust from a kerf formed in the work piece by the blade whensaid angle guide is operatively positioned in the mill.
 8. The angleguide of claim 7 wherein said block member forms two steps, a firstlower step extending upwardly from said base plate adjacent to theposition of a metal insert when said insert is attached to said baseplate, a second upper step being recessed from said first step andextending above the level of a band saw blade of said mill when saidguide is operatively positioned, said air inlet port and said hollowpassageway being formed in said second upper step.
 9. The angle guide ofclaim 7 wherein said air inlet port is located near one side of saidblock member which is opposite the side of said block member upon whichsaid passageway opens.
 10. The angle guide of claim 7 wherein said airinlet port opens upon an upper surface of said block member which facesa direction which is perpendicular to the opening containing side ofsaid block member.
 11. The angle guide of claim 7 wherein said air inletport is interiorally threaded to receive an exteriorally threaded airoutlet connector of an air hose from an external source of high pressureair.
 12. The angle guide of claim 7 further comprising a band sawstabilizing metal insert attached to said base plate adjacent to saidblock member, said insert comprising a block of material selected fromthe group consisting essentially of aluminum bronze and aluminum brass.13. The angle guide of claim 12 wherein said block is generallyrectangularly shaped and includes rounded edges on opposite ends thereofwhich are position on said base member so as to extend transversely withrespect to a band saw blade to be stabilized when said angle guide isdisposed in an operative position in said mill.
 14. The angle guide ofclaim 12 wherein said block is generally rectangularly shaped andincludes beveled edges on opposite ends thereof which are positioned onsaid angle guide so as to extend transversely with respect to a band sawblade to be stabilized when said angle guide is disposed in an operativeposition in said mill.
 15. The angle guide of claim 12 wherein saidmetal insert is removably attached to said base plate.
 16. The angleguide of claim 15 wherein said metal insert defines at least onerecessed countersunk hole therethrough for insertion of a cap screwtherein in close conforming relation in said hole below the level of asaw blade opposable surface of said insert for removable attachment ofsaid insert to said base plate.
 17. The angle guide of claim 16 furthercomprising at least one cap screw for insertion into said countersunkhole in close conforming relation such that a cap of said cap screw isbelow a saw blade opposable surface of said insert when said angle guideand insert are operatively positioned in said mill.
 18. The angle guideof claim 17 wherein said at least one fastener includes a flat head capscrew defining a hex socket for insertion therein of a hex wrench forsecuring and removing said insert to and from said base plate.
 19. A sawblade guide for stabilizing a blade of a saw mill comprising a baseplate, a block disposed on said base plate and recessed from a free endof said base plate, said block defining an interiorly threaded blindhole forming an air inlet port opening onto a surface thereof forattachment thereto of an exteriorly threaded air outlet connector of aremote high pressure air source, said block also defining a hollow airpassageway extending from said air inlet port to an opening on a side ofsaid block which faces a work piece when said guide is disposed in anoperative position in a saw mill, said opening being at about the samelevel as that of a saw blade being stabilized by said guide when saidguide is disposed in said operative position.
 20. The saw blade guide ofclaim 19 wherein said air inlet port opens onto a base surface of saidbase plate.